Analysis of four major misunderstandings when adjusting the suitability of offset printing ink In the film production process, it is often necessary to adjust the suitability of the ink used. To meet the printing needs of different products and different papers. Adjust the ink to suitability. This is achieved by adding appropriate auxiliary materials to the ink. Because people have different understandings of auxiliary materials or have prejudices, so. In actual production, it is possible to enter some "misunderstandings" and produce unsatisfactory results.
1. Replace the varnish with a detackifier
during production. When printing large-area solid plates. When the ink is not easy to be uniformed during the transfer process of the ink roller, or the phenomenon of paper "fluffing" or rough printing occurs. Generally it is caused by the high viscosity of the ink. Detackifier and varnish can reduce the viscosity of ink, but their properties are not exactly the same. While reducing the viscosity of the ink, the detackifier also has the effect of inhibiting the drying of the ink and reducing the adhesion of the ink layer to the paper. In the ink, the varnish can reduce the viscosity of the ink and increase the fluidity of the ink. Although it has an effect on the drying speed of the ink layer, it is not obvious. If an excessive amount of detackifier is blindly added to the ink to reduce the viscosity of the ink, it is likely to cause the phenomenon of "not drying" or "chalking" of the ink layer. So pay attention to the "quantity" problem when adding detackifiers, and never take it lightly. Keep it within a proper comparison. And at the same time increase the amount of desiccant. To avoid the above-mentioned adverse consequences.
2. Use white ink as a dilution agent
Individual color inks need to add a diluent to the original ink to make it a light-colored ink, and this diluent should be colorless and transparent. Brightening paste and Weili oil are both ideal dispersants, which have the function of not changing the hue of the original ink but can change the depth of the original ink. If you use white ink as a thinner. Is not appropriate. Because white ink has a white hue, it will change the hue of the original ink so that the original ink tends to be white and tender jade ink instead of being a light-colored ink. This goes against the operator's original intention of needing light-colored ink. And in the offset printing process. If there are too many white ink components in the ink, because the white ink pigment particles have a high proportion, the pigment particles will pile up on the printing plate or blanket during the ink delivery process. And cause the ills of rough imprinting.
Three, do not distinguish between the different work of anti-adhesive and detackifier
The anti-sticking agent is added to the ink to prevent or reduce the sticking problem of the paper surface and back after printing. And to reduce ink viscosity, it mainly plays its role in the process of ink transfer during printing. If the two are confused without distinction, other problems are likely to arise. If a detackifier is added to the ink in order to prevent the ink on the front and back of the paper from sticking, the "non-drying" nature of the detackifier will prolong the drying time of the ink layer of the printed product and counteractly make the surface of the paper more prone to sticking. on the other hand. If more anti-sticking agent is added in order to reduce the viscosity of the ink in the printing process, it will not only fail to reduce the viscosity. It will also "roughen" the ink. Make it tarnish and affect the quality of the product.
Four, do not pay attention to the difference between red oil and white oil
Although both red dry oil (also known as drill dry oil) and white dry oil (also known as dry oil) are desiccants for printing inks, they have different compositions because of their different compositions. The drying form of the layer is different. The addition of red dry oil to the ink can greatly increase the rate of oxidation and conjunctivation on the surface of the ink layer, that is, rapid drying on the surface of the ink layer. However, the red dry oil cannot promote the dry operation speed inside the ink layer to be greatly improved. White oil has the property of promoting the overall drying of the ink layer. When the white dry oil is added to the ink, the drying speed on the surface and inside of the ink layer can be greatly improved. therefore. When we are using desiccant. Must pay attention to the difference between the two dry forms. E.g. For the ink layer surface dry. Red dry oil is better than white dry oil. However, if the solid printing plate or paper with a thicker ink layer has poor drying performance on the ink layer due to its pH, if the operator simply uses red dry oil as the ink oil drying device, the ink layer is likely to appear. The surface is dry but the inside is not very dry. Such a printed product can easily wipe off the ink layer in the case of rubbing with external force, leaving the printed product with traces of being rubbed, which affects the product quality. In addition, when printing gold ink and silver ink, it is necessary to add a desiccant. Generally, red dry oil should be used instead of white dry oil. Because the white dry oil is combined with gold ink and silver ink. It has a tendency to make the original ink color darker. This will affect the gloss of gold and silver ink.